1. Field of the Invention
The present invention relates to a safety device and to a container provided with such a device.
The invention relates, more particularly, to a safety device forming a valve for releasing a pressurized gas in a hazardous situation, comprising a body defining a gas flow channel extending between an upstream first end intended to be brought into contact with a source of pressurized gas and a downstream second end intended to be brought into contact with the external atmosphere, the device including a plug located on the channel to prevent the gas from flowing between the upstream end and the downstream end given a normal situation, the plug being meltable and/or frangible so as to free the passage for the gas in the event of a hazardous situation with the pressure and/or the temperature exceeding a predetermined threshold.
2. Related Art
Inflammable gas bottles, in particular for mobile hydrogen energy applications, are equipped with a device for emptying the gaseous contents of the bottle if it is in a fire situation so as in this way to prevent it from exploding. This relates in particular to composite bottles of type IV.
Such a device often includes a thermal fuse, that is to say a entactic metal that has to melt when exposed to the temperature of the fire so as to create a leak that empties the bottle and thus prevents it from exploding.
In many fire situations, when the fuse releases the gas (especially hydrogen), the gas ignites and creates a flame of relatively large length depending on the pressure characteristics of the gas and on the geometry of the discharge orifice.
Opening the fuse clearly allows the gas at risk to be discharged. However, under certain conditions the gas does not ignite spontaneously. The gas release may thus be mixed with the ambient air and form an inflammable cloud of relatively large volume, the explosion (or even detonation) of which may prove to be disastrous, in particular in confined and obstructed configurations (typically in an underground parking lot or a tunnel).
However, it is often preferable to form a flame (even of great length) since the associated (radiation) effects are judged to be less than those of a gas cloud exploding.
A known solution consists in choosing a geometry of the gas discharge orifice that favors spontaneous ignition of said gas.